Machine for forming high-pressure nonmetallic tubing



J. i. NASH June 5, 1956 MACHINE FOR FORMING HIGH-PRESSURE NON-METALLIC TUBING 4 Sheets-Sheet 1 Filed May 19, 1952 Alifax/VH June 5, 1956 J. J. NASH4 2,748,831

MACHNE FOR FORMING HIGH-PRESSURE NON-METALLIC TUBING Filed May 19, 1952 4 sheets-sheet 2 INVENToR.

JOHN J. NASH /z BY June 5, 1956 2,748,831

MACHINE FOR FORMING HIGH-PRESSURE NoN-METALLIC TUBING J. J. NASH 4 Sheets-Sheet 5 Filed May`l9, 1952 INVENToR. JOHN J. NASH June 5, 1956 J. J. NASH MACHINE FOR FORMING HIGH-PRESSURE NoN-METALLIC TUBING Filed May 19, 1952 4 Sheets-Sneek 4 .NNTOE .E .0E $2.200 x JNVENTOR. JOHN J. NASH United States Patent O MACHINE FOR FORMlNG HIGH-PRESSURE NON- METALLIC TUBING John J. Nash, Normandy, Mo., assignor, by mesne assignments, to American Fixture, Inc., a corporation of Missouri Application May 19, 1952, Serial No. 288,649

1 Claim. (Cl. 154 1.8)

This invention relates in general to certain new and useful improvements in high-pressure non-metallic tubing and methods of making the same and is related to application Serial No. 288,648, liled contemporaneously herewith.

As pointed out in the abovernentioned copending application, conventional metallic pipe presents a number of technological problems in industrial and related piping installation, such as crude oil gathering systems, subterranean oil and gas pipe lines, and steam and pressure systems employed in certain types of naval vessels to be used as mine sweepers or for similar purposes. These technological elds of application are illustrations of uses in which metallic piping and tubing are found to be unsatisfactory and for which some type of dielectric nonmagnetic piping or tubing becomes almost essential.

It is, therefore, one of the primary objects of the present invention to provide a dielectric non-magnetic pipe or tube formed of synthetic materials i and which is extremely strong, rigid, and capable of sustaining relatively high internal or bursting pressure and is, therefore, adapted for use in a wide variety of engineering applications for which hitherto only metal piping has been suiliciently strong.

Another object of the present invention is to provide piping or tubing formed of synthetic materials including thermosetting resins.

It is another object of the present invention to provide piping or tubing of the type stated which is initially formed as a spiral winding, the convolutions of which are integrally bonded together by polymerization of thermosetting resins forming a component of the piping or tubing and resulting in an extremely strong rigid, durable structure.

It is a further object of the present invention to provide a method and apparatus for manufacturing spiral wound synthetic piping or tubing of the type stated.

It is also an object of the present invention to provide apparatus for manufacturing piping or tubing of the type stated in a continuous manner.

In the accompanying drawings (four sheets) Figure 1 is a side elevational view, partly broken away and in section, of synthetic pipe manufacturing apparatus constructed in accordance with and embodying the present invention;

.Figure 2 is a top plan View of the mandrel rotating or winding device forming a part of the apparatus of the present invention;

Figure 3 is a fragmentary sectional View taken along line 3 3 of Figure 2;

Figures 4 and 5 are fragmentary sectional views taken along lines 4 4 and 5 5, respectively, of Figure 3;

Figure 6 is a fragmentary sectional View taken along line 6 6 of Figure 4;

Figures 7, 8, and 9 are fragmentary sectional views taken along lines 7 7, 8 8, and 9 9, respectively, of Figure 2;

Figure 10 is a fragmentary sectional view taken along line 10 10 of Figure l;

2,748,831 Patented June 5, 1956 rice Figure 11 is a fragmentary sectional view taken along line 11 11 of Figure l0;

Figure 12 is a fragmentary perspective View of a piece of synthetic pipe manufactured in accordance with and embodying the present invention; l

Figure 13 is a top plan view of a modied form of synthetic pipe manufacturing apparatus constructed in accordance with and embodying the present invention;

Figures 14, 15, 16, 17, 18, 19, 20, and 21 are fragmentary sectional views taken along lines 14 14, 15 15, 16-16, 17 17, 18-18, 19 19, 20 20, and 21 21, respectively, of Figure 13; and

Figure 22 is a fragmentary perspective View taken along line 22 22 of Figure 20. i y Y Referring now in more detail and by reference characters to the drawings, which illustrate practical embodiments of 'the present invention, A designates a synthetic pipe or tube manufacturing machine comprising four short upstanding legs or posts 1 arranged in longitudinally aligned pairs for rigidly supporting spaced parallel horizontal slide rods 2. Shiftably mounted by means of depending bearing lugs 3 upon and extending horizontally between the slide rods 2 in upwardly spaced relation thereto, is a traversing table 4. Bolted or otherwise suitably secured upon the other face of the traversing table 4 is a vertically upwardly extending roll-stand 5 comprising a pair of spaced parallel sideplates 6 for removably supporting a roll-shaft 7 which, in turn, supports a roll 8 of wax-coated kraft paper tape from which a web is unrolled and passed over a guide roller 9 and thence applied to the mandrel to form a continuous spiral Windmg w.

Similarly mounted upon the upper face of the table 4 and on opposite sides thereof rearwardly of the roll-stand 5 (the lower end of Figure 2 being referred to as tbe rearward end) are roll-stands 10, 10', identical in all respects to the roll-stand 5 for supporting rolls of tape 11, 11', respectively, formed preferably of woven tiberglass or other similar material. Also mounted on the table 4 inwardly of and in line with the roll-stands 10, 10', respectively, are open-topped dipping tanks 12, .12', each having guide rollers 13, 14, 15, a pair of squeegee rollers 16, 17, and an upwardly inclined drain-lip 18. It should be noted in this connection that the roll-stands S, lil, 10', are positioned at an oblique angle to the longitudinal axis of the machine A, as shown in Figure 2.

The liber-glass tapes 11, 11', are passed over the guide rollers 13 down into the tanks 12, 12', respectively, which are filled with a suitable synthetic resin. The tapes 11, 11', pass beneath guide rollers 14 and thence upwardly between the pair of squeegee rollers 16, 17, which are formed of soft rubber and are held together with suilicient tension to squeeze off any excess of liquid which may tend to be carried up upon the faces of the tapes 11, 11', as they move out of the synthetic resin dipping bath and pass over the guide rollers 15.

Midway between the forward and rearward ends, respectively, of the slide rods 2 is a mandrel winding stand 19 consisting of two upright or vertical pedestals 20, y21, bolted or otherwise securely mounted upon the oor in alignment along the longitudinal center-line of the machine A, as shown in Figure 2. p

The pedestal 20 is provided at its upper end with a rectangular boxlike housing 22 for shiftably Vsupporting a rectangular bearing block 23 biased rearwardly toward the pedestal 21 by means of compression springs 24, 25, and supported by an outwardly extending guide rod 26 which projects slidably through an end wall 27 of the housing 22 and on its outer projecting end is provided With an enlarged stop head 28. On its inwardly presented face, the bearing block 23 is provided with a bearing `34 is further provided with a driving shaft 38 axiallyl aligned with the spindle 32 and integrally provided on its outer end with a diametrally enlarged chuck 39 having a recess 40 of rectangular cross-section for receiving the reduced rectangular end portions 41 of a winding mandrel 42. Inwardly of its rectangular end, the mandrel is turned down in the provision of an annular groove 43. As will be seen by reference to Figure 2, both ends of the mandrel 42 are identical and the rectangular end portions 41 are provided with axially drilled circular recesses 44, so that either end may be inserted into the chuck 39 and the operators consequently do not have to be concerned with which end of the mandrel 42 is presented toward the chuck 39.

Journaled at its ends in and extending horizontally bctween the pedestals 20, 21, is a lead-screw 45 threadedly engaged in a depending lug 46 formed integrally on the underside of the table 4. Adjacent the pedestal 20, the lead-screw 45 is rigidly provided with a sprocket 47 connected by a roller-chain 48 which passes around a driving-sprocket 49 pinned upon the drive-shaft 50 of an electric motor 51.

The mandrel 42 is lifted by the operator into position between the pedestals 20, 21, and one end placed against the spindle point 33 which centers itself within the circular recess 44, as shown in Figure 9. The operator then pushes the mandrel 42 outwardly against the bias of the springs 24, 25, so that the opposite end portion 41 may be slipped into the recess 40 of the chuck 39.

Thereupon, the mandrel 42 is manually wrapped with one or two spiral turns of the wax coated kraft paper tape to form a protective wrapping w, the end of which is preferably held in place by an annular wrapping y of some suitable pressure-sensitive ribbon-like material, such as Scotch tape, for example. The motors 37, 51, which are conventionally connected in parallel through a cornmon main switch (not shown) to a source of electric current, are turned on simultaneously and a few turns of the winding w run onto the mandrel 42. Then, the resin saturated ends of the tapes 11, 11', are manually wrapped around the winding w, as shown in Figure 8, so as to start right-handed and left-handed spiral windings x, x. which will progress forwardly along the mandrel 42 and the lead-screw 45 are turned. It should be noted in this connection that the oblique angle at which the rollstands 5, 10, are positioned, the pitch of the lead-screw 45, and the speed of rotation of the motors 37, 51, are so arranged in relation to each other as to produce smooth overlying spiral windings w, x, x. This turning or winding operation should, however, be performed at a selected rate of speed which is convenient for the operator so as to permit the operator to observe the winding operation and see to it that each winding is smoothly and cohesively wound in place, sufficient tension being maintained on the rollers 13, 14, 15, 16, 17, to pull the webs of tapes 11, 11', tightly around the mandrel 42 as it is being wound. When a sufficient length has been wound upon the mandrel 42 to provide a tube or pipe of desired length, the webs of tape from the rolls 8, 11, 11', are severed with a knife or scissors and the trailing portion manually laid down and patted in place on the mandrelwound portion. Thereupon, the mandrel 42 is manually removed from the winding stand 19 and placed between upstanding V-shaped ight blocks 52 mounted at spaced intervals along parallel conveyor chains 53 trained around sprockets 55, 56, and extending horizontally through a tunnel-shaped oven 57 having suitable heat sources, such as a bank of infra-red lamps 58. The blocks 52 are paired and spaced from each other transversely of the oven 57 by a sufficient distance so as to tit more or less freely within the annular groove 43 of the mandrel. The mandrel 42 is thus carried slowly through the oven 57 and therein subjected to a predetermined curing temperature for a selected period of time. It will be understood that the temperature and time may be varied depending upon the polymerization characteristics of the resin with which the webs of tape from the rolls 11, 11', have been im' pregnated or coated.

At its forward end, the oven 57 is provided with a cooling chamber 59 in which air is blown downwardly upon the wound mandrels 42 by a fan 60 mounted prei'- erably in the upper wall of the cooling chamber 59. Ultimately, the mandrels 42 are carried forwardly out of the open forward end of the oven 57 for removal from the blocks 52 in any suitable manner. The operator then may remove the mandrel 42 by holding the pipe-forming external winding and tapping one end of the mandrel 42 gently with a rawhide hammer, driving it axially out of winding to leave a completed section of pipe I. The removed mandrel 42 may then be placed in a conventional conveyor (not shown) for return to the winding stand 10. The interior wax coated kraft wrapping w assures easy and ready parting between the pipe P and the mandrel 42, so that the mandrel 42 may be readily removed. After the mandrel 42 has been removed, one protruding end of the wrapping w may be manually grasped and pulled outwardly, with the result that the entire interior core or wrapping w can readily be pulled out, leaving an extremely smooth, accurately sized, precisely cylindrical interior surface or bore within the pipe P. The marginal ends of the pipe P may then be sawed off in any contventional manner and the burrs reamed out or sanded to produce a finished section of pipe P, as shown in Figure l2, having a selected or desired length.

lf desired, it is possible to provide a modified form of pipe-forming machine B, as shown in Figures l3 to 22, inclusive, comprising a stationary base plate 70 suitably mounted in any conventional manner upon a iloor or other supporting structure. Suitably mounted upon the upper face of the base plate 70, adjacent the rear end thereof (reference being made to the right end of Figure 13), is a conventional tube winding unit M. Since the tube winding unit M may be of any suitable design, it has been schematically designated in Figure 13 by dotted lines, and is shown as including a driving motor 71, a stationary mandrel 72, and roll stands 73 for supporting rolls of cardboard tape which are spirally wound on the mandrel and glued to each other to provide a continuous cardboard tube t. Also forming a part of the tube winding unit M is a wax applicator device generally designated 74 for coating the mandrel 72 so that the tube t will slide freely along the mandrel 72 and similarly desig nated at 75 is a spiral Wound driving belt assembly which eneircles the tube t to drive it spirally forwardly along the mandrel 72 and to cause the two spirally wound cardboard plies of the tube t to adhere firmly to each other.

Supported above the base plate 70 forwardly of the tube winding unit M by means of legs 76 is a wax tank 77 having horizontal top and bottom .valls 7S, 79, respectively. The bottom wall 79 is provided with an elongated applicator spout 80 located directly above the mandrel 72. The top wall 78 is provided with a removable filling plug 31 and a vertically adjustable gate 82 aligned with the spout 80 for controlling the ow of liquid wax therethrough. The bottom wall 79 is also provided with pairs of depending arms 83, 83', for operatively supporting rotary wax-spreading brushes 84, 84', directly driven by electric motors 85, 85', respectively, for spreading the wax smoothly in a thin film over the surface of the twoply spiral winding or tube t, as shown in Figure l5. Forwardly of the wax-tank 77 is a pair of conical motor driven polishing or wax-smoothing buffers 86, 86'.

Bolted upon and extending vertically upwardly from the base plate 70 is a steady rest 87 provided with a plurality of freely rotating rollers 8S for supportive engagement with the outer waxed surface of the winding or tube t, as shown in Figure 16.

Also bolted to the base plate 70 on oppossite sides of the mandrel 72 forwardly of the steady rest 87 are roll stands S9, each comprising spaced parallel side plates 89 having a removable shaft 90 for supporting a roll 91 of woven liber-glass tape 92. Iournaled at its ends in and extending horizontally between the plates 89' is a guide roller 93. In front of each roll stand 89 is an impregnating tank 94 iilled with a solution of resin or similar heat setting plastic material and having guide rollers 95, 96, 97, and a pair of squeegee rollers 98, 99. The fiberglass tapes, after passing through the tank 94 and having excess resin-solution removed, are wrapped around the tube t to form a two-ply winding z which feeds forwardly along with the tube t. Preferably the mandrel 72 is provided with a very slight forward taper, that is to say, the forward end is several thousandths of an inch smaller than the rear end, so that the tube t will draw smoothly and continuously along the mandrel 72 and ol the end, as shown in Figure 19.

Forwardly of the machine A is a conventional tunnel type oven 100 through which the tube z passes and beyond the oven 100 is a conventional ying cut-off saw 101 mounted in a pneumatically shifted slide 102 which is, in turn, mounted on a traversing table 103 fed to and fro lengthwise of the tube-path by a feed-screw 104 driven by a reversing motor 105, as shown in Figures 20 and 22. The hydraulic cylinder is actuated by two valves 106, 106', which are located at opposite ends of the traversing table 103 and are actuated by impact therewith to shift the slide 102 away from the tube z as the table 103 reaches the forward end of its stroke and shift it in toward the tube z as the traversing table reaches the rearward end of its stroke. The valve system is conventional and is, therefore, not described in detail. 'Ihe speed of the reversing motor 105 and the pitch of the feed-screw 104 are such that during forward movement the traversing table 103 will have the same speed as thel forward speed of the tube z and the length of the path of movement of the traversing table will determine the length of the section of tube z which is cut off during each stroke. For instance, if the motor 105 reverses at the same speed as it feeds forwardly the length of tube z which is cut off will be twice the length of the traversing table path.

After the sections are cut oi, they may be placed in a bath of water or other similar solvent capable of loosening the cardboard inner core or tube t, which can then be manually removed or cleaned out with a stiff tube brush, leaving a clean-bore rigid section of plastic pipe.

Actual field tests with synthetic pipe constructed in accordance with the present invention have revealed that the material has practically no affinity for the wax, parain, and tars usually present in crude oil and, therefore, can be used in a crude oil gathering system for months on end without accumulating a bore-reducing internal layer or deposit of paraffin, Wax, and the like. Pressure tests have shown that synthetic pipes and tubing made in accordance with the present invention have a bursting strength comparable to that of metallic pipes and tubes of similar weight, size, and thickness and are, therefore, entirely satisfactory for use in shipboard steam-pipe installation and the like.

ln addition to this, iield tests have also shown that synthetic pipes made in accordance with the present invention are electrolytically inert when buried beneath the earth or submerged beneath a body of water in the manner of conventional pipe and gas lines and, therefore, can be used for pipeline purposes without wrapping or other electrolysis-preventing expedients and affords every indication of extremely long life and durability in this type of engineering application.

It should be understood that changes and modifications in the form, construction, arrangement, and combination of the several parts of the high-pressure non-metallic tubing and in the steps of its production may be made and substituted for those herein shown and described without departing from the nature and principle of my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

A machine for forming non-metallic piping and tubing which comprises an elongated mandrel operatively mounted for rotation about its longitudinal axis, a slide mounted adjacent to the mandrel for movement along a path parallel to the longitudinal axis of the mandrel, means for moving the slide along said path in timed relation to the rate of rotation of the mandrel, a plurality of roll-stands mounted on the slide for supporting rolls of tape, said roll-stands being positioned in respect to the mandrel in such a manner as to feed tape upon the mandrel along a line angularly disposed with respect to the longitudinal axis of the mandrel, whereby to simultaneously form a series of overlying spiral windings upon the mandrel.

References Cited in the tile of this patent UNITED STATES PATENTS 1,215,934 Heckman Feb. 13, 1917 1,795,876 McCoy Mar. 10, 1931 1,990,248 Parker Feb. 5, 1935 2,048,360 Spanel et al. July 2l, 1936 2,296,781 Farny Sept. 22, 1942 2,354,556 Stahl July`25, 1944 2,402,038 Goldman et al. June 11, 1946 2,478,181 Coker et al. Aug. 9, 1949 2,653,887 Slayter Sept. 29, 1953 

